code: def testAggregateIndexedSlices(self):
      t0 = math_ops._as_indexed_slices(
          constant_op.constant([[1.0, 2.0], [0, 0], [3.0, 4.0]])
      )
      t1 = math_ops._as_indexed_slices(
          constant_op.constant([[0.0, 0.0], [5, 6], [7.0, 8.0]])
      )
      total = constant_op.constant([[1.0, 2.0], [5, 6], [10.0, 12.0]])
      result = cross_device_utils.aggregate_tensors_or_indexed_slices(
          [t0, t1]
      )
      self.assertIsInstance(result, indexed_slices.IndexedSlices)
      self._assert_values_equal(total, result)
  
imports: from absl.testing import parameterized
  from tensorflow.python.distribute import combinations
  from tensorflow.python.distribute import cross_device_utils
  from tensorflow.python.distribute import device_util
  from tensorflow.python.eager import test
  from tensorflow.python.framework import constant_op
  from tensorflow.python.framework import dtypes
  from tensorflow.python.framework import indexed_slices
  from tensorflow.python.framework import ops
  from tensorflow.python.framework import test_util
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import math_ops
label_desc: Use image node_id 3 for calling the IndexedSlicesUtilsTest obj's underlying member method code with example usage: obj.testAggregateIndexedSlices() without return types